The distribution of neuron-specific gene family member 1 in brain and germ cells: Implications for the regulation of germ-line development by brain.

Vesicular acidification at early endosomes dissociates endocytosed receptor-ligand complexes. The ligands, receptors, or both are then directed to late endosomes for degradation or recycled back to the plasma membrane. Of neuron-specific gene (NSG) family members, early endosomal protein neuron-specific gene family member 1 (NSG1) is the most important in receptor recycling. In this study, we characterized chicken NSG1 (cNSG1). We found several functional sites related to endocytotic machinery in cNSG1 that were highly conserved with most other vertebrate NSG1 proteins. We examined the tissue and duration specificity and the temporal and spatial patterns of cNSG1 expression. cNSG1 expression was preferentially located in all regions of the brain, neuroendocrine glands, and spinal cord. Unexpectedly, cNSG1 expression was strongly detected during male and female germ-line development. Expression of NSG1 in two apparently unrelated cell types such as neurons and germ cells suggests NSG1 roles in neurons and germ-cells chemotaxis and endocytotic machinery.